Electric vaporizer.



C. L. DAVIS.

ELECTRIC VAPOBIZEB.

unicum! Hmm In n. 1913.

1,091,637. Patented Mar.31,19111 'UNITED STATES PATENT OFFICE.

CHARLES L. DAVIS, OF DETROIT, MICHIGAN, SSIGrNOR.v OF ONE-HALF TO HARRY W.

, FROST, 0F DETROIT, MICHIGAN.

ELECTRIC VAPORIZER.

specification of Letters Patent.

Patented Mar. 31, 1914.

- Application inea May 9, 1913. sen'ai No. 766,580.

more 'particularly designed for use in con-f nection with explosion engines using kerosene or other liquid'fuel of low volatility.

It is one of the objects of the invention to obtain a' construction which in operation will discharge only vapor, and in which the oil is quickly vaporized and in proportion to the demand.

With these objects in view the invention comprises various features of construction as hereinafter set forth.

In the drawings: Figure l is a diagrammatic view showing the vaporizer when out of action; Fig. 2 is a similar View with the vaporizer in operation; and Fig. 3 is a cross section on line m-cc of Fig. 2.

In the operation of explosion engines by kerosene or other relatively heavy liquid hydrocarbons, the chief difficulty experienced is in obtaining an explosive mixture for starting. Variouspre-heaters for the oil, electric and other constructions, have been employed, but these, while heating the oil and perhaps discharging the mixed oil and vapor, have not proven efficient for the discharge of vapor alone. As a consequence, more or less` of the liquid hydrocarbon is carried into the engine cylinder where it is carbonized, producing difficulties with the igniter and other objectionable results. With my improved construction, the diiliculties are avoided-rst,by holding the liquid back from the discharge nozzle by the pressure of the vapor generated; second, by varying theheating surface exposed to the liquid to produce a corresponding variation in the quantity of vapor generated; and third, by reventing communication of heat to the b y of liquid and in restricting the amount of liquid in contact with the heater to increase its speed of operation and eiiicientfy. f'

As shown A is a suitable receptacle for the oil or other liquid to be vaporized, and which is preferably maintained at a constant head or hydrostatic level by suitable means (not shown).

B is the vapor discharge nozzle, which is preferably arranged with its discharge orifice approximately at the level of the liquid 1n the receptacle A.

C is an electric heater within the nozzle B, arranged slightly below the discharge end thereof, but in a position to be normally immersed in the liquid. i

D is a conduit connecting the receptacle A with the nozzle B at a point below 'the lower end of t-he heater C andv preferably having a bend or trap E therein, preventing any thermo-Siphon circulation of the' liquid.

The proportion of theparts just described 1s such that the rate of vapor generation produced by the heater C when imm'rsed'in the liquid is greater than that which can be discharged through the restricted orifice F under the hydrostatic pressure of the liquid in. the receptacle'A. As a consequence, the 1n1tial operation of the heater will develop a vapor or gaseous pressure within the nozzle, which will drive back the liquid against the hydrostatic pressure until a portion of the heating surface is exposed to the vapor only. In the continued generation the vapor evolved by the boiling liquid will be compelled to pass the exposed portion of the heating surface which will produce a superheating, discharging from the nozzle a gas that will not readily condense. This will commingle with air in any suitable air mixing chamber (not shown) such as the induction conduit of th'e engine.

Another effect that is automatically produced by the construction above` described is the regulation of the heat in Vaccordance with the discharge of the vapor; As is well known, the electrical resistance of most metallic resistors increases with increase in temperature. It is also a fact that the'heat generated in a resistor may be much more rapidly dissipated when iny contact with a liquid than by the contact of a gas. Thus initially the heater C lbeing completely immersed in a liquid and cooled thereby Awill be of a lower electrical resistance 'than when the liquid is driven back and a portion o'f the surface is exposed onlyV to vapor. This will permit a larger current volume to pass lthrough the resistor at the start with a corresponding heat generation, while after a- Aeo sov

portion of the surface is exposed to va'por, 110

the increase in temperature will increase the resistance and diminish the current. This, in turn, will diminish the heat generation, which will lessen the rate of vapor generation, and consequently the amount of the heater exposed to the liquid will be automatically regulated to the amount of vapor discharged from the nozzle.

Inv the specific construction of the electric heater, I preferably employ a naked coil G arranged within a bifurcated metallic member H, preferably formed by a tube having opposite sideA portions thereof cut away. One terminal of the coil G is electrically connected to the outer end of the tube H, while the other terminal is connected to a central rod l' passing out through the tube 'and' insulated therefrom. The rod l may be attached to one of the terminals of the electric generator, while the tube H maybe grounded. This forms a convenient construction which is readily insertible in either the induction conduit for the engine, in the nozzle of the carbureter, or in any other place where it is desired to place the vaporizer.

What I claim as my invention is:

1. A vaporizer, comprising a`vapor discharge nozzle, means for establishing a hydrostatic' level of the liquid to be vaporized below the discharge end of said nozzle, and a heater for the liquid within said nozzle, having a rate of vapor generation in excess of the rate of vapor discharge from said nozzle under the hydrostatic pressure of the liquid, whereby said liquid isy driven back from the nozzle by vapor pressure.

2. A vaporizer, comprising a vapor discharge nozzle, a supply connection for the liquid to be vaporized having a normal hydrostatic level below the discharge orifice of said nozzle, and a heater immersed in said liquid when at normal level having a rate of vapor generation in excess of the rate of vapor discharge under normal hydrostatic pressure, sufficient to drive' back the liquid and to expose a portion of the heating surface to vapor only.

3. A vaporizer, comprising a vapor dis-` charge nozzle, a supply connection for the liquid to be vaporized, having a normal hydrostatic level below the discharge orifice of said nozzle, and a heater having its surface exposed to liquid contact when at normal level vand of a vapor generating capacity-in excess. ofthe rate of vapor discharge under normal hydrostatic pressurel suicient' jto drive back 'the liquid 4from a portion of the heating surface and exposing the same to vapor only. Y

4. A vaporizer, comprising a vapor discharge nozzle, a supply connection or the liquid to be vaporized having a normal hydrostatic level below thedischarge orifice of said nozzle, and an electric heater having its surface exposed to the liquid within said nozzle, the parts being so organizedthat the heat generated by said heater is regulated by a `variable exposure of the heating surface of the same to the liquid and vapor.

5. A vaporizer, comprising a vapor discharging nozzle, means for supplying the liquid to be vaporized under a predetermined pressure thereto, and a heater for the liquid within said' nozzle having a rate ofvapor generation in excess of the rate of vapor discharge from said nozzle under the pressure upon the liquid, whereby said liquid is driven back in the nozzle by vapor pressure.

6. A vaporizer, comprising a vapor discharge nozzle, a supply connection for liquid to be vaporized having a normal hydrostatic level, and a heater immersed in said liquid when at normal level having a rate of vapor generation'in excess of the rate of vapor-discharge under the hydrostatic pressure, suiiicient to drive back the liquid and expose a portion-of the heating surface to vapor only.

7. A vaporizer, comprising a vapor discharge nozzle, means for supplying liquid to be vaporized under a predetermined pressure thereto, and a heater for the liquid within said nozzle, said nozzle having its discharge restricted to a rate less than the rate of vapor generation, whereby the liquid is driven back in the nozzle by,v vapor pressure.

`8. A vaporizer, comprising a vapor discharge nozzle, means for supplying liquid to be vaporized under a predetermined pressure, and a heater for the liquid within said nozzle, the rateof vapor generation being proplortioned relative to the rate of vapor disc arge, whereby the liquid is drivenbacl inthe nozzle by the vapor pressure arising .from the difference in rate of the vapor generation and discharge.

testimony whereof 1 vaffix my signature in presence of two witnesses.

CHARLES L. DAVIS. Witnesses: JAMES P. BARRY,

DELBERT COLLINS. 

